Colt developed the design basis memorandum (FEL 2) and basic engineering package (FEL 3). The scope of the project included a new S-Zorb unit, SO2 recovery process (CANSOLV) modifications to two FCCU gas plants, distillate desulphurizing unit, sulphur plant and various utilities. For the first FCCU, Colt developed the design for 30 PPM. For the second FCCU, Colt developed a HYSYS simulation for the fractionator and gas plant. This included reconciling the simulation against test-run data and benchmarking to establish a base case.This project was an extensive revamp involving the replacement of much of the existing equipment. The project impacted the plant’s FCCU, the gas plant, crude unit and distillate desulphurization unit. An innovative approach was used to minimize turnaround hours and their effect on operations